1. Field of the Invention
This invention directs itself to aircraft systems for vertical take-off and landings. In particular, this invention directs itself to a VTOL aircraft having vertical thrust augmented by suction generated aerodynamic lift. Further, this invention is directed to a VTOL Aircraft having a plurality of rotors extending beneath a portion of the fuselage for displacing air downwardly therefrom. More in particular, a portion of the airflow on the suction side of the rotor blades is displaced from above the fuselage for creating a low pressure region thereabove. The remaining portion of the suction airflow is drawn from a central portion of the underside of the fuselage, thereby creating an updraft of rising air which is accelerated by the rotor blade suction so as to contact the fuselage bottom surface and flow thereover to create a high pressure region in juxtaposition therewith. The low pressure region on the upper surface of the fuselage and the high pressure layer on the bottom surface, together in combination provide an aerodynamic lift.
2. Prior Art
Vertical take-off and landing aircraft are well known in the art. The best prior art known to the Applicant is disclosed in U.S. Pat. Nos. 1,405,035; 1,816,707; 3,752,417; 3,117,747; 3,054,578; 3,525,485; 3,172,116; 3,424,404; 3,372,891; 4,187,999; 4,941,628; 2,967,029; 4,202,518; 3,829,043; 2,308,477; 3,514,053; 2,912,188; 3,155,342; 3,199,809; 3,633,849; 3,767,141; 3,414,077; 2,922,277; 3,278,138; 3,284,027; 3,469,804; and, 3,632,065.
In some prior art systems, such as that disclosed in U.S. Pat. No. 1,405,035, aircraft are disclosed which are capable of ascending and descending vertically. In such systems a rotor may be mounted beneath the fuselage to provide the lifting power for a vertical ascent, or for controlling the vertical descent. However, such systems do not disclose or suggest the augmentation of the lifting thrust using suction generated aerodynamic lift.
In other systems, such as that disclosed in U.S. Pat. Nos. 1,816,707 or 3,752,417, vertical take-off and landings are made possible by propeller generated lift. The rotor blades are disposed in duct-like structures formed in the fuselage, for directing the airflow downward to create the thrust utilized to lift the aircraft. Here again, such fans are not augmented by suction generated aerodynamic lift, as provided by the instant invention.
In another prior art system shown in U.S. Pat. No. 2,912,188 engine thrust output is selectively changed between horizontal and vertical directions. However, the weight to lift ratio has been found to be unacceptably low and fuel consumption and noise levels are high. As in previously described references the vertical thrust is not augmented by the suction generated aerodynamic lift.